VEGETABLE PEODUCTS. 155 



called Protein compounds, and exist, in greater or less quanti- 

 ties, in nearly or quite all the vegetable products that come to 

 our table. 



Protein^ C^^, Hsg, Ng, O^, (from proteuo, I have the fii'st 

 place), is a compound obtained by certain agencies on flesh, 

 white of an egg, milk curd, and hence has been made the basis 

 of Fihriri, Albumen, and Casein, which are found not only in 

 flesh, egg, and milk, but are diffused, under some slight modifi- 

 cations, throughout the vegetable kingdom. 



302. The nitrogenized substance of flour is obtained by 

 washing a piece of dough inclosed in a thin linen cloth in much 

 water. We get a mass of gray elastic substance, consisting of 

 coagulated albumen and what has been called gluten. The 

 gluten is soluble in boiling alcohol, and precipitates on cooling, 

 and this has been called fibrin. The albumen does not differ 

 from the white of an egg. Legumin, or vegetable casein, is 

 found with starch in the Leguminous plants. The three varie- 

 ties may be derived from the same juice in the following man- 

 ner: Take some Turnip juice, and when first pressed out it is 

 clear. By standing it becomes turbid by the deposition of the 

 fibrin, which coagulates spontaneously. Boil a portion of the 

 liquid, and the albumen coagulates. Add a small quantity of 

 vinegar to another portion, and it will coagulate the casein. 

 The nitrogenized compound of corn is called zeine. 



The Formula for these compounds is : 



20 Proteiiie-f-S^-f P for albumen. 

 S -f P for fibria 

 " -f-S for casein. 



These form the nutritious portions oi the plants we eat, being 

 most abundant in flour and beans. 



303. Another class of vegetable nJtrogenize<l products are 

 the organic bases or alkalies. The most common are the fol- 

 lowing: 



Daturin is a base found in the Datura stramonium, James- 

 town weed, very poisonous, and is the active principle in that 

 powerful plant 



Morphin, NC^g, H.^©, Og, is one of the active ingredients in 

 Opium, the one whose action is supposed to occasion sleep. 



301. "What the nitrogenized eompounds called ? Constitution of pro- 

 tein ? Forms the basis'of what ? — 302. How is the nitrogenized materials 

 of flour obtained ? What portion called fibrin ? Where is casein found? 

 How may albumen, casein, and fibrin be obtained from the same juice ? 

 What are the formuhi for these compounds? Mention some of them. — 

 803. What other class of nitrogenized compounds? Mention some ot 

 them. 



